1. Field of the Invention
Embodiments disclosed herein generally relate to a downhole debris retrieval tool for removing debris from a wellbore. Further, embodiments disclosed herein relate to a downhole tool for debris removal with maximum efficiency at a low pump rates.
2. Background Art
A wellbore may be drilled in the earth for various purposes, such as hydrocarbon extraction, geothermal energy, or water. After a wellbore is drilled, the well bore is typically lined with casing. The casing preserves the shape of the well bore as well as provides a sealed conduit for fluid to be transported to the surface.
In general, it is desirable to maintain a clean wellbore to prevent possible complications that may occur from debris in the well bore. For example, accumulation of debris can prevent free movement of tools through the wellbore during operations, as well as possibly interfere with production of hydrocarbons or damage tools. Potential debris includes cuttings produced from the drilling of the wellbore, metallic debris from the various tools and components used in operations, and corrosion of the casing. Smaller debris may be circulated out of the well bore using drilling fluid; however, larger debris is sometimes unable to be circulated out of the well. Also, the well bore geometry may affect the accumulation of debris. In particular, horizontal or otherwise significantly angled portions in a well bore can cause the well bore to be more prone to debris accumulation. Because of this recognized problem, many tools and methods are currently used for cleaning out well bores.
One type of tool known in the art for collecting debris is the junk catcher, sometimes referred to as a junk basket, junk boot, or boot basket, depending on the particular configuration for collecting debris and the particular debris to be collected. The different junk catchers known in the art rely on various mechanisms to capture debris from the well bore. A common link between most junk catchers is that they rely on the movement of fluid in the well bore to capture the sort of debris discussed above. The movement of the fluid may be accomplished by surface pumps or by movement of the string of pipe or tubing to which the junk catcher is connected. Hereinafter, the term “work string” will be used to collectively refer to the string of pipe or tubing and all tools that may be used along with the junk catchers. For describing fluid flow, “uphole” refers to a direction in the well bore that is towards the surface, while “downhole” refers to a direction in the well bore that is towards the distal end of the well bore.
The use of coiled tubing and its ability to circulate fluids is often used to address debris problems once they are recognized. Coiled tubing runs involving cleanout fluids and downhole tools to clean the production tubing are often costly.
Accordingly, there exists a need for a more efficient tool and method for removing debris from a wellbore.